As the Occupy Wall Street protests have grown in Manhattan and spread across the US, they are increasingly being compared to the right-wing tea parties. Vice president Joe Biden has spoken for many when he said the two movements share a common frustration while the Los Angeles Times went further and asked: "Is Occupy Wall Street a tea party for Democrats?"

Put that question to Amy Kremer, chairman of one of the largest tea party groups, the Tea Party Express, and you get a pretty forthright response. She likens the OWS protesters to "a kid having a temper tantrum because their parents won't buy them the whole ice-cream store. Their demands are ridiculous, absurd."

Kremer, who lives in Atlanta Georgia but spends much of her time travelling across America with the Tea Party Express battle bus, accepts that there is a shared anger at the core of both phenomenon: disapproval of the way the banks were allowed to get away with it after the 2008 financial melt-down. But she thinks the OWS organisers are going after the wrong target. "This isn't Wall Street's fault. It's Washington's fault – and that's where they should focus their efforts."

She is also scathing about the loose political aims of the protesters. "You've got to be realistic in your demands and efficient in how you set about achieving them. Holding rallies doesn't do anything other than attract people to the movement. "The question is what do you do then? How do direct all that support and energy towards action, towards influencing legislation?"

Most tea party figures follow Kremer's analysis that there is some degree of overlap between OWS and their movement. Brendan Steinhauser of Freedomworks, a Washington-based group that runs a nationwide network of tea party off-shoots, says that "the tea parties arose out of opposition to the Wall Street bail-outs in 2008 – that was the event that gave birth to them, so yes it's funny that the Occupy Wall Street guys are also against phoney capitalism and we agree about that."

But that's where the affinity ends, he says. He observed the Occupy DC rally outside the Capitol and says what he saw there were "the same leftists, the same union organisers, the same Castro supporters you see on every leftist demonstration. It's same-old, same-old."

David Webb has been watching the unfolding of the New York protests particularly closely. He organises a Manhattan-based group called Tea Party 365, and has been interested to see how the OWS shapes up by comparison.

His conclusion is that the protests are rapidly being hijacked by interested parties. "The transport unions are getting behind it, rabble rousing and agitating, moveon.org is imposing its progressive agenda on it."

His point is interesting, because exactly the same criticisms have been made about the tea parties – that they are just being manipulated by powerful and wealthy puppet-masters such as big corporations and the oil tycoons the Koch brothers.

"I accept that there will always be institutions or individuals who want to take advantage of any grass-roots movement," Webb says. "They tried to take advantage of us, but by and large we said no. We don't yet know whether Occupy Wall Street will do the same."

Webb also dislikes what he regards as the hostile and disrespectful spirit of the OWS marches. He's organised rallies that have seen more than 12,000 tea partiers assemble in Manhattan, "but at the end of the day we left the streets clean and empty. We weren't out to disrupt like this lot."

Eric Alterman, James Antle, Ayesha Kazmi, Sally Kohn, Doug Guetzloe, Frances Fox Piven and Douglas Rushkoff: Both are grassroots populist movements with a common anger at bailed-out banks, but where does the resemblance end?